Slavery: A series of erotic games (book 04)
"Just as Dominants sometimes use chastity belts to control female slaves, cock cages are used to control males. This one is relatively benign. It only prevents him from getting an erection without suffering pain. Some have sharp points on the inside and there are some which have protrusions which are inserted into the urethra. Some dominants also pierce the genitals of their male slaves, in the cock, balls or both."
"Why do it?" Wendy asked.
"Because we are subordinating our will to our Masters. Our bodies, our sexuality, even our orgasms belong to our Dominant. It's why I spanked Rhonda for cumming without your permission. I cannot have sex without his permission, not even to masturbate. No